The goals of this project are: (1) to establish and define a cell culture transformation system for identification of individuals predisposed to cancer genetically or by virtue of exposure to environmental carcinogens; (2) to develop human cell transformation systems, with particular emphasis on epithelial cells, in order to study host factors regulating cell transformation and the mechanisms of carcinogenesis by chemicals, viruses, hormones and x-irradiation; (3) to isolate and characterize oncogenes from human or primate tumors; and (4) to develop and test measures to prevent and/or control cell transformation and the neoplastic event for eventual application in primates, including humans.